Every (original buyer) in that neighborhood signed an acknowledgement that they realized they were moving in next to a medical waste incinerator plant. It is really hard for the city to say, 'Stericycle, move. These people don't like you.' They knew.—North Salt Lake City Manager Barry Edwards

SALT LAKE CITY — Utah air quality regulators on Thursday revamped their case against the West's only medical waste incineration plant, modifying the allegations to reflect higher penalties.

It's the latest move in an ongoing dispute between Stericycle and North Salt Lake neighborhood residents who are pushing to shut down the incinerator and clean up the air.

"We want to keep pressure on the state to do something," said Natasha Hincks-Henderson, who is among the neighboring residents in the North Salt Lake Foxboro subdivision who said they are frustrated by the plant. She said the ultimate goal is to get Stericycle to use another method to dispose of medical waste.

Stericycle received a revised notice of violation that more accurately reflects the days the plant was violating the emission limits of its permit. The notice begins a new time frame for the company to respond to what the state describes as serIous violations of its permit.

Community meetings and protests have been staged this summer against Stericycle, ramping up after state regulators alleged in May the company was in violation of its permit at its North Salt Lake plant and had also falsified records.

Although several groups have called on state regulators and Gov. Gary Herbert to shut down the incinerator, such action isn't likely any time soon.

Bryce Bird, director of the Utah Division of Air Quality Control, said the permit can not be revoked until after the appeal process, which could take years.

"The most productive use of our time is getting additional emission controls in place as quickly as possible," Bird said. "It is not in their best interest or our best interest to start a legal fight."

The plant has been in compliance with its permit since June and has been subject to routine monitoring, Bird said.

"There are not any outstanding issues where they are still violating our rules."

In May, the division issued a notice of violation to the company, asserting it had violated emission limits established by its permit with the state and also falsified those records to demonstrate lower emission levels.

Regulators became suspicious in late 2011 and through 2012 during a series of three stack tests to determine the level and nature of pollutants released into the air from the plant. Tests are supposed to be conducted at the maximum production or combustion rate and reflect normal, operational variances, Bird said.

According to the notice of violation, Stericycle at first attempted to blame tests that were in violation of its emission limits on a flawed laboratory analysis. After the division obtained additional information, it found that a Dec. 27-28, 2011, test exceeded levels for hazardous pollutants, as well as nitrogen oxides, or highly reactive gases.

Bird said there were repeated problems with other tests and discrepancies that popped up in the company's logs that misled regulators, adding that information was manipulated that was not reflective of normal operating conditions.

That aspect of the air pollution case has been turned over to the Environmental Protection Agency and the Department of Justice for a criminal investigation, Bird said.

The state Division of Air Quality twice extended a deadline to come to a settlement — in which the company agrees to pay civil penalties and take additional steps to reduce its emissions.

Bird said the fine could be significant because it is a case the division takes seriously.

"Our intent is to hold them accountable," Bird said. "We're looking at additional controls and what else can be done to ultimately improve the situation for residents there."

Critics of Stericycle say autoclaves could be used to sterilize the waste before it is buried at landfill — a clean air alternative that won't leave neighbors worried about their health. The EPA estimates 90 percent of medical waste is incinerated in the United States, with the greatest concern being the resulting emissions.

"This is a great neighborhood with tons of parks and walkways, tons of lids and five elementary schools," Hincks-Henderson said. "This place should not be around where people are living."

North Salt Lake City Manager Barry Edwards said the city is waiting to see how the state investigation plays out. Stericycle has a conditional use permit first approved by the city planning commission in 1990.

Over the years, residents and activists have raised concerns with city leaders over the emission of dioxins and other pollutants, but Edwards said the permit can't be revoked until the state settles its case or if criminal charges are filed.

He noted that businesses like Stericycle have to exist somewhere and residents of Foxboro were aware of the plant's existence when they moved in.

"Every (original buyer) in that neighborhood signed an acknowledgement that they realized they were moving in next to a medical waste incinerator plant," he said, adding that some sort of disclosure would have been made to subsequent owners. "It is really hard for the city to say, 'Stericycle, move. These people don't like you.' They knew."

Hincks-Henderson acknowledges there may have been some disclosure about Stericycle when she purchased her home nearly five years ago, but she said it only detailed there would be bright lights and truck traffic.